A reactor equipped with a plasmonic catalyst to produce either methane or carbon monoxide is being developed for operation under concentrated sunlight

In the SPOTLIGHT project, a reactor equipped with a plasmonic catalyst to produce either methane or carbon monoxide is being developed for operation under concentrated sunlight.

The SPOTLIGHT consortium will test a prototype in the solar furnace at DLR in Cologne, Germany. Here, a heliostat reflects sunlight upon a concentrator, which consists of 160 honeycomb-shaped mirrors. They bundle the light and create a bell-shaped flux distribution with a flux density of up to 4500 kW/m² at the focal point.

For the experiments, only a part of the available solar power is required and DLR is developing and testing a technical device (flux guide) that guides the incoming concentrated sunlight in a way, that it illuminates the reactor with a homogenous flux density of up to 20 kW/m². To find an optimal design of the flux guide, a ray-tracing model is implemented to easily test various flux guide geometries. The model is now being used to design the flux guide.

Since one goal of SPOTLIGHT is to achieve also a continuous operation of the reactor, LED light is considered, instead of a pure solar operation, to compensate missing solar power in case of cloudy weather or for operation at night. Different options to establish combined solar and LED operation have been assessed.

The option which uses the flux guide to shape and guide not only concentrated sunlight, but also LED light to illuminate the reactor, emerged as the favourite one. Consequently, the flux guide must yield a homogenous reactor illumination for both light sources. To consider all specifics of the different components, the flux guide is designed in close cooperation with the project partners.